20600640 has 168 divisors, whose sum is σ = 74176128. Its totient is φ = 5237760.

The previous prime is 20600639. The next prime is 20600641. The reversal of 20600640 is 4600602.

20600640 is a `hidden beast` number, since 2 + 0 + 600 + 64 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (20600639) and next prime (20600641).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20600641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66085 + ... + 66395.

Almost surely, 2^20600640 is an apocalyptic number.

20600640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20600640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37088064).

20600640 is an abundant number, since it is smaller than the sum of its proper divisors (53575488).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20600640 is a wasteful number, since it uses less digits than its factorization.

20600640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 357 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 20600640 is about 4538.7927910404. The cubic root of 20600640 is about 274.1323175013.

The spelling of 20600640 in words is "twenty million, six hundred thousand, six hundred forty".